There are toys and teaching aids that use a mechanical connector to quickly assemble electronic circuits. Sooner or later these components are connected to a power source such as a battery. If the circuit allows too much current to flow, certain devices may become extremely hot and even explode.
Fuses may be connected in series with the power source that will open when excessive current flows. Since most inexpensive fuses must be replaced, this process is inconvenient and allows the child or student the option of using a conductor that eliminates the protection device. Mechanically resetable fuses are expensive and some can be held in the on position to eliminate the protection feature of the fuse.
Another safety problem exists when polarized capacitors are installed backwards in electronic circuits. The capacitors leakage current will increase significantly and the device will rise in temperature and may even explode. Many existing products do not consider the safety of the child or student when allowing for the insertion of capacitors and other “off the shelf” electronic components.